COLIFORMS, E. COLI, CAMPYLOBACTER, AND SALMONELLAE IN A COUNTERFLOW BROILER SCALDER WITH A DIP TANK

Authors: Cason Jr, John; Hinton Jr, Arthur

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2006
Publication Date: 7/16/2006
Citation: Cason Jr, J.A., Hinton Jr, A. 2006. Coliforms, e. coli, campylobacter, and salmonellae in a counterflow broiler scalder with a dip tank [abstract]. Poultry Science Association Meeting Abstract. 85 (Suppl. 1):134.

Interpretive Summary: During poultry processing, carcasses are dipped in tanks of hot water to make it possible to remove the feathers. Large numbers of bacteria are removed at the same time and can move between carcasses. Scald tank designs have been modified over the last few years to try to reduce the chance of bacterial cross-contamination between carcasses. This paper reports numbers of bacteria found in scald water and in carcass rinses in an operating processing plant with several relatively new design features. It appears that multiple-tank scalder designs reduce the numbers of bacteria in scald water and the opportunities for cross-contamination between carcasses via the water.

Technical Abstract: Suspended bacteria were enumerated in scald water and carcass rinse samples from a commercial broiler processing plant with a multiple-tank, counterflow scalder. After five-wk-old broilers had been processed for eight hours, water samples were taken on six days from each of three scald tanks and from a dip tank located between defeathering machines. Coliforms, E. coli, and Campylobacter were enumerated and the Most Probable Number (MPN) of salmonellae was determined in water samples and in rinses of carcasses removed from the processing line immediately after defeathering. Mean coliform concentrations in Tanks 1, 2, and 3 were 4.6, 2.5, and 1.6 log10(cfu/ml), respectively. E. coli concentrations followed the same pattern with means of 4.4, 2.1, and 1.4 in Tanks 1, 2, and 3, respectively, with significant differences (P<.05) in the concentrations of both coliforms and E. coli between the tanks. Mean Campylobacter concentration in four positive samples from Tank 1 was 4.0 log10(cfu/ml), but only one water sample from Tank 2 and none from Tank 3 were Campylobacter positive. Coliforms and E. coli were found in dip tank samples in only two instances, with no isolations of Campylobacter or salmonellae. Mean numbers of coliforms, E. coli, and Campylobacter in carcass rinses were 3.1, 2.7, and 3.3 log10(cfu/ml). Salmonellae were isolated from five of six water samples from Tank 1 with a mean MPN of 13.3/100mL, but were isolated from only three of six water samples from Tank 2 and two of six from Tank 3. Salmonellae were isolated from half (18/36) of all carcass rinses. Most bacteria suspended in scald water were found in the first tank, with no Campylobacter or salmonellae found in the dip tank. Counterflow, multiple-tank scalders appear to reduce the opportunity for cross-contamination during scalding.